1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (c) 2001-2003 Cluster File Systems, Inc.
6 * This file is part of Lustre, http://www.lustre.org.
8 * Lustre is free software; you can redistribute it and/or
9 * modify it under the terms of version 2 of the GNU General Public
10 * License as published by the Free Software Foundation.
12 * Lustre is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with Lustre; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #ifndef AUTOCONF_INCLUDED
23 #include <linux/config.h>
25 #include <linux/kernel.h>
27 #include <linux/string.h>
28 #include <linux/stat.h>
29 #include <linux/errno.h>
30 #include <linux/smp_lock.h>
31 #include <linux/unistd.h>
32 #include <linux/version.h>
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
37 #include <linux/stat.h>
38 #include <asm/uaccess.h>
40 # include <asm/segment.h>
43 #include <linux/pagemap.h>
44 #include <linux/smp_lock.h>
46 #define DEBUG_SUBSYSTEM S_LLITE
48 //#include <lustre_mdc.h>
49 #include <lustre_lite.h>
50 #include "llite_internal.h"
51 #include <linux/lustre_compat25.h>
53 #define VMA_DEBUG(vma, fmt, arg...) \
54 CDEBUG(D_MMAP, "vma(%p) start(%ld) end(%ld) pgoff(%ld) inode(%p) " \
55 "ino(%lu) iname(%s): " fmt, vma, vma->vm_start, vma->vm_end, \
56 vma->vm_pgoff, vma->vm_file->f_dentry->d_inode, \
57 vma->vm_file->f_dentry->d_inode->i_ino, \
58 vma->vm_file->f_dentry->d_iname, ## arg); \
61 struct ll_lock_tree_node {
63 struct list_head lt_locked_item;
65 ldlm_policy_data_t lt_policy;
66 struct lustre_handle lt_lockh;
68 struct inode *lt_inode;
71 int lt_get_mmap_locks(struct ll_lock_tree *tree,
72 unsigned long addr, size_t count);
74 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
77 struct ll_lock_tree_node * ll_node_from_inode(struct inode *inode, __u64 start,
78 __u64 end, ldlm_mode_t mode)
80 struct ll_lock_tree_node *node;
82 OBD_ALLOC(node, sizeof(*node));
84 RETURN(ERR_PTR(-ENOMEM));
86 node->lt_inode = inode;
87 node->lt_oid = ll_i2info(inode)->lli_smd->lsm_object_id;
88 node->lt_policy.l_extent.start = start;
89 node->lt_policy.l_extent.end = end;
90 memset(&node->lt_lockh, 0, sizeof(node->lt_lockh));
91 INIT_LIST_HEAD(&node->lt_locked_item);
97 int lt_compare(struct ll_lock_tree_node *one, struct ll_lock_tree_node *two)
99 /* To avoid multiple fs deadlock */
100 if (one->lt_inode->i_sb->s_dev < two->lt_inode->i_sb->s_dev)
102 if (one->lt_inode->i_sb->s_dev > two->lt_inode->i_sb->s_dev)
105 if (one->lt_oid < two->lt_oid)
107 if (one->lt_oid > two->lt_oid)
110 if (one->lt_policy.l_extent.end < two->lt_policy.l_extent.start)
112 if (one->lt_policy.l_extent.start > two->lt_policy.l_extent.end)
115 return 0; /* they are the same object and overlap */
118 static void lt_merge(struct ll_lock_tree_node *dst,
119 struct ll_lock_tree_node *src)
121 dst->lt_policy.l_extent.start = min(dst->lt_policy.l_extent.start,
122 src->lt_policy.l_extent.start);
123 dst->lt_policy.l_extent.end = max(dst->lt_policy.l_extent.end,
124 src->lt_policy.l_extent.end);
126 /* XXX could be a real call to the dlm to find superset modes */
127 if (src->lt_mode == LCK_PW && dst->lt_mode != LCK_PW)
128 dst->lt_mode = LCK_PW;
131 static void lt_insert(struct ll_lock_tree *tree,
132 struct ll_lock_tree_node *node)
134 struct ll_lock_tree_node *walk;
135 rb_node_t **p, *parent;
139 p = &tree->lt_root.rb_node;
143 walk = rb_entry(parent, struct ll_lock_tree_node, lt_node);
144 switch (lt_compare(node, walk)) {
152 lt_merge(node, walk);
153 rb_erase(&walk->lt_node, &tree->lt_root);
154 OBD_FREE(walk, sizeof(*walk));
162 rb_link_node(&node->lt_node, parent, p);
163 rb_insert_color(&node->lt_node, &tree->lt_root);
167 static struct ll_lock_tree_node *lt_least_node(struct ll_lock_tree *tree)
170 struct ll_lock_tree_node *node = NULL;
172 for ( rbnode = tree->lt_root.rb_node; rbnode != NULL;
173 rbnode = rbnode->rb_left) {
174 if (rbnode->rb_left == NULL) {
175 node = rb_entry(rbnode, struct ll_lock_tree_node,
183 int ll_tree_unlock(struct ll_lock_tree *tree)
185 struct ll_lock_tree_node *node;
186 struct list_head *pos, *n;
191 list_for_each_safe(pos, n, &tree->lt_locked_list) {
192 node = list_entry(pos, struct ll_lock_tree_node,
195 inode = node->lt_inode;
196 rc = ll_extent_unlock(tree->lt_fd, inode,
197 ll_i2info(inode)->lli_smd, node->lt_mode,
200 /* XXX better message */
201 CERROR("couldn't unlock %d\n", rc);
203 list_del(&node->lt_locked_item);
204 OBD_FREE(node, sizeof(*node));
207 while ((node = lt_least_node(tree))) {
208 rb_erase(&node->lt_node, &tree->lt_root);
209 OBD_FREE(node, sizeof(*node));
215 int ll_tree_lock(struct ll_lock_tree *tree,
216 struct ll_lock_tree_node *first_node,
217 const char *buf, size_t count, int ast_flags)
219 struct ll_lock_tree_node *node;
223 tree->lt_root.rb_node = NULL;
224 INIT_LIST_HEAD(&tree->lt_locked_list);
225 if (first_node != NULL)
226 lt_insert(tree, first_node);
228 /* To avoid such subtle deadlock case: client1 try to read file1 to
229 * mmapped file2, on the same time, client2 try to read file2 to
231 rc = lt_get_mmap_locks(tree, (unsigned long)buf, count);
235 while ((node = lt_least_node(tree))) {
236 struct inode *inode = node->lt_inode;
237 rc = ll_extent_lock(tree->lt_fd, inode,
238 ll_i2info(inode)->lli_smd, node->lt_mode,
239 &node->lt_policy, &node->lt_lockh,
244 rb_erase(&node->lt_node, &tree->lt_root);
245 list_add_tail(&node->lt_locked_item, &tree->lt_locked_list);
249 ll_tree_unlock(tree);
253 static ldlm_mode_t mode_from_vma(struct vm_area_struct *vma)
255 /* we only want to hold PW locks if the mmap() can generate
256 * writes back to the file and that only happens in shared
258 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
263 static void policy_from_vma(ldlm_policy_data_t *policy,
264 struct vm_area_struct *vma, unsigned long addr,
267 policy->l_extent.start = ((addr - vma->vm_start) & CFS_PAGE_MASK) +
268 (vma->vm_pgoff << CFS_PAGE_SHIFT);
269 policy->l_extent.end = (policy->l_extent.start + count - 1) |
273 static struct vm_area_struct * our_vma(unsigned long addr, size_t count)
275 struct mm_struct *mm = current->mm;
276 struct vm_area_struct *vma, *ret = NULL;
279 /* No MM (e.g. NFS)? No vmas too. */
283 spin_lock(&mm->page_table_lock);
284 for(vma = find_vma(mm, addr);
285 vma != NULL && vma->vm_start < (addr + count); vma = vma->vm_next) {
286 if (vma->vm_ops && vma->vm_ops->nopage == ll_nopage &&
287 vma->vm_flags & VM_SHARED) {
292 spin_unlock(&mm->page_table_lock);
296 int lt_get_mmap_locks(struct ll_lock_tree *tree,
297 unsigned long addr, size_t count)
299 struct vm_area_struct *vma;
300 struct ll_lock_tree_node *node;
301 ldlm_policy_data_t policy;
308 /* we need to look up vmas on page aligned addresses */
309 count += addr & (~CFS_PAGE_MASK);
310 addr &= CFS_PAGE_MASK;
312 while ((vma = our_vma(addr, count)) != NULL) {
313 LASSERT(vma->vm_file);
315 inode = vma->vm_file->f_dentry->d_inode;
316 policy_from_vma(&policy, vma, addr, count);
317 node = ll_node_from_inode(inode, policy.l_extent.start,
321 CERROR("not enough mem for lock_tree_node!\n");
324 lt_insert(tree, node);
326 if (vma->vm_end - addr >= count)
328 count -= vma->vm_end - addr;
334 /* FIXME: there is a pagefault race goes as follow (only 2.4):
335 * 1. A user process on node A accesses a portion of a mapped file,
336 * resulting in a page fault. The pagefault handler invokes the
337 * ll_nopage function, which reads the page into memory.
338 * 2. A user process on node B writes to the same portion of the file
339 * (either via mmap or write()), that cause node A to cancel the
340 * lock and truncate the page.
341 * 3. Node A then executes the rest of do_no_page(), entering the
342 * now-invalid page into the PTEs.
344 * Make the whole do_no_page as a hook to cover both the page cache
345 * and page mapping installing with dlm lock would eliminate this race.
347 * In 2.6, the truncate_count of address_space can cover this race.
349 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
352 struct file *filp = vma->vm_file;
353 struct ll_file_data *fd = LUSTRE_FPRIVATE(filp);
354 struct inode *inode = filp->f_dentry->d_inode;
355 struct lustre_handle lockh = { 0 };
356 ldlm_policy_data_t policy;
358 struct page *page = NULL;
359 struct ll_inode_info *lli = ll_i2info(inode);
360 struct lov_stripe_md *lsm;
362 __u64 kms, old_mtime;
363 unsigned long pgoff, size, rand_read, seq_read;
367 if (lli->lli_smd == NULL) {
368 CERROR("No lsm on fault?\n");
372 /* start and end the lock on the first and last bytes in the page */
373 policy_from_vma(&policy, vma, address, CFS_PAGE_SIZE);
375 CDEBUG(D_MMAP, "nopage vma %p inode %lu, locking ["LPU64", "LPU64"]\n",
376 vma, inode->i_ino, policy.l_extent.start, policy.l_extent.end);
378 mode = mode_from_vma(vma);
379 old_mtime = LTIME_S(inode->i_mtime);
382 rc = ll_extent_lock(fd, inode, lsm, mode, &policy,
383 &lockh, LDLM_FL_CBPENDING | LDLM_FL_NO_LRU);
387 if (vma->vm_flags & VM_EXEC && LTIME_S(inode->i_mtime) != old_mtime)
388 CWARN("binary changed. inode %lu\n", inode->i_ino);
390 lov_stripe_lock(lsm);
391 inode_init_lvb(inode, &lvb);
392 obd_merge_lvb(ll_i2dtexp(inode), lsm, &lvb, 1);
395 pgoff = ((address - vma->vm_start) >> CFS_PAGE_SHIFT) + vma->vm_pgoff;
396 size = (kms + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
399 lov_stripe_unlock(lsm);
400 ll_glimpse_size(inode, LDLM_FL_BLOCK_GRANTED);
402 /* XXX change inode size without ll_inode_size_lock() held!
403 * there is a race condition with truncate path. (see
405 /* XXX i_size_write() is not used because it is not safe to
406 * take the ll_inode_size_lock() due to a potential lock
407 * inversion (bug 6077). And since it's not safe to use
408 * i_size_write() without a covering mutex we do the
409 * assignment directly. It is not critical that the
410 * size be correct. */
411 /* region is within kms and, hence, within real file size (A).
412 * We need to increase i_size to cover the read region so that
413 * generic_file_read() will do its job, but that doesn't mean
414 * the kms size is _correct_, it is only the _minimum_ size.
415 * If someone does a stat they will get the correct size which
416 * will always be >= the kms value here. b=11081 */
417 if (i_size_read(inode) < kms) {
419 CDEBUG(D_INODE, "ino=%lu, updating i_size %llu\n",
420 inode->i_ino, i_size_read(inode));
422 lov_stripe_unlock(lsm);
425 /* If mapping is writeable, adjust kms to cover this page,
426 * but do not extend kms beyond actual file size.
427 * policy.l_extent.end is set to the end of the page by policy_from_vma
429 lov_stripe_lock(lsm);
431 obd_adjust_kms(ll_i2dtexp(inode), lsm,
432 min_t(loff_t, policy.l_extent.end + 1,
433 i_size_read(inode)), 0);
434 lov_stripe_unlock(lsm);
436 /* disable VM_SEQ_READ and use VM_RAND_READ to make sure that
437 * the kernel will not read other pages not covered by ldlm in
438 * filemap_nopage. we do our readahead in ll_readpage.
440 rand_read = vma->vm_flags & VM_RAND_READ;
441 seq_read = vma->vm_flags & VM_SEQ_READ;
442 vma->vm_flags &= ~ VM_SEQ_READ;
443 vma->vm_flags |= VM_RAND_READ;
445 page = filemap_nopage(vma, address, type);
446 LL_CDEBUG_PAGE(D_PAGE, page, "got addr %lu type %lx\n", address,
448 vma->vm_flags &= ~VM_RAND_READ;
449 vma->vm_flags |= (rand_read | seq_read);
451 ll_extent_unlock(fd, inode, ll_i2info(inode)->lli_smd, mode, &lockh);
455 /* To avoid cancel the locks covering mmapped region for lock cache pressure,
456 * we track the mapped vma count by lli_mmap_cnt.
457 * ll_vm_open(): when first vma is linked, split locks from lru.
458 * ll_vm_close(): when last vma is unlinked, join all this file's locks to lru.
460 * XXX we don't check the if the region of vma/lock for performance.
462 static void ll_vm_open(struct vm_area_struct * vma)
464 struct inode *inode = vma->vm_file->f_dentry->d_inode;
465 struct ll_inode_info *lli = ll_i2info(inode);
468 LASSERT(vma->vm_file);
470 spin_lock(&lli->lli_lock);
471 LASSERT(atomic_read(&lli->lli_mmap_cnt) >= 0);
473 atomic_inc(&lli->lli_mmap_cnt);
474 if (atomic_read(&lli->lli_mmap_cnt) == 1) {
475 struct lov_stripe_md *lsm = lli->lli_smd;
476 struct ll_sb_info *sbi = ll_i2sbi(inode);
479 spin_unlock(&lli->lli_lock);
483 count = obd_join_lru(sbi->ll_dt_exp, lsm, 0);
484 VMA_DEBUG(vma, "split %d unused locks from lru\n", count);
486 spin_unlock(&lli->lli_lock);
491 static void ll_vm_close(struct vm_area_struct *vma)
493 struct inode *inode = vma->vm_file->f_dentry->d_inode;
494 struct ll_inode_info *lli = ll_i2info(inode);
497 LASSERT(vma->vm_file);
499 spin_lock(&lli->lli_lock);
500 LASSERT(atomic_read(&lli->lli_mmap_cnt) > 0);
502 atomic_dec(&lli->lli_mmap_cnt);
503 if (atomic_read(&lli->lli_mmap_cnt) == 0) {
504 struct lov_stripe_md *lsm = lli->lli_smd;
505 struct ll_sb_info *sbi = ll_i2sbi(inode);
508 spin_unlock(&lli->lli_lock);
512 count = obd_join_lru(sbi->ll_dt_exp, lsm, 1);
513 VMA_DEBUG(vma, "join %d unused locks to lru\n", count);
515 spin_unlock(&lli->lli_lock);
519 #ifndef HAVE_FILEMAP_POPULATE
520 static int (*filemap_populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
522 static int ll_populate(struct vm_area_struct *area, unsigned long address,
523 unsigned long len, pgprot_t prot, unsigned long pgoff,
529 /* always set nonblock as true to avoid page read ahead */
530 rc = filemap_populate(area, address, len, prot, pgoff, 1);
534 /* return the user space pointer that maps to a file offset via a vma */
535 static inline unsigned long file_to_user(struct vm_area_struct *vma, __u64 byte)
537 return vma->vm_start + (byte - ((__u64)vma->vm_pgoff << CFS_PAGE_SHIFT));
541 /* XXX put nice comment here. talk about __free_pte -> dirty pages and
542 * nopage's reference passing to the pte */
543 int ll_teardown_mmaps(struct address_space *mapping, __u64 first, __u64 last)
548 LASSERTF(last > first, "last "LPU64" first "LPU64"\n", last, first);
549 if (mapping_mapped(mapping)) {
551 unmap_mapping_range(mapping, first + CFS_PAGE_SIZE - 1,
552 last - first + 1, 0);
558 static struct vm_operations_struct ll_file_vm_ops = {
561 .close = ll_vm_close,
562 .populate = ll_populate,
565 int ll_file_mmap(struct file * file, struct vm_area_struct * vma)
570 ll_stats_ops_tally(ll_i2sbi(file->f_dentry->d_inode), LPROC_LL_MAP, 1);
571 rc = generic_file_mmap(file, vma);
573 #if !defined(HAVE_FILEMAP_POPULATE)
574 if (!filemap_populate)
575 filemap_populate = vma->vm_ops->populate;
577 vma->vm_ops = &ll_file_vm_ops;
578 vma->vm_ops->open(vma);
579 /* update the inode's size and mtime */
580 rc = ll_glimpse_size(file->f_dentry->d_inode, 0);